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Why investigate reef noise

Prof John Montgomery and Dr Craig Radford talk about why they conduct research on reef noise. They discuss the potential for their findings and how modern noises can interfere with the settlement of reefs.

Transcript

PROF JOHN MONTGOMERY The finding that passive acoustics, that ambient underwater sound, is an important orientation mechanism for fish is quite new. It’s really only in the last kind of 5–8 years that we have done these experiments to show that the sound is there, sorted out exactly who is making the sound, looked at the propagation of that sound off the reef and shown that, behaviourally, that the fish will respond to that. So they will orient to the sound, that they will actually show up thinking that there is a reef there when there isn’t.

DR CRAIG RADFORD This work is important if we think, especially in New Zealand, in terms of export and fisheries and aquaculture. With all these species, they all have a larval cycle in which the larvae are exported off the coast. So they have all got to find their way back to the coast in order to make it into the adult phase and to be fished. We need to know how these animals are finding their way back, especially if they are using sound to the extent that we think.

Sound in the world’s oceans has more than doubled since the 70s, so if these little fellows are using underwater sound and we are increasing the noise levels in the ocean, we are going to start to see effects where they might not be able to hear the reef because there is too much noise from ships, from coastal power stations, offshore turbines maybe.